Rotary internal-combustion engine



F. KELLER, In.

ROTARY INTERNAL COMBUSTION ENGINE.

APPLICATION FILED SEPT-8, 192g. 1

2 SHEETS-SHEET I.

F. KELLER, In. ROTARY INTERNAL comsusnou ENGINE.

APPLICATION FILED SEPT- 8. I920.

Patented Dec. 27, 1921.

2 SHEETS-$HEET 2- FIBJI.

F'IE5.XE.

WENT R w/ wvssses FRED KELLER, JR., 0F PITTSBURGH, PENNSYLVANIA.

ROTARY INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent. Patented D60. 27, 1921.

Application filed September 8, 1920. Serial No. 409,030.

To aZZ whom it may concern:

Be it known that I, FRED KELLER, Jr., a citizen of the United States, residing at 2912 East St, N. S. Pittsburgh. in the county of Allegheny, and State of Pennsylvania, have invented a new and useful Rotary Internal-Combustion Engine, of which the following is a specification.

My invention relates to rotary explosive, or internal combustion, engines, and consists in structural improvements which make for efiiciency, and smoothness in running, together with. simplicity and cheapness in manufacture.

In the accompanying drawings Figure I is a view in medial section through an engine embodying my invention, the plane of section being indicated by the line II, Fig. II; Fig. II is a transverse section of the same, the plane of section being immediately within the cover plate of the casing, and being indicated by the line IIII, Fig. I; Fig. III is a view in plan of the drum or rotor; Fig. IV is a view in medial section of a portion of the shaft with the drum or rotor in place upon it but otherwise dismembered. The plane of section of Fig. IV is indicated by the line IVIV, Fig. III. Fig. V is a view in plan of a portion of the cover plate of the casing. Figs. VI, VII and VIII, are views in side elevation, in front elevation, and in vertical section, respectively, of one of the pistons, detached. Fig. VI shows the link-like piston stem. The plane ofsection of Fig. VIII is indicated by the line VIIIVIII, Fig. VI. Fig. IX is a view inside elevation of the main inion, and, in longitudinal section, of the sleeve which carries it; Fig. X shows in two views, in front and in side elevation, a certain pinion with its integrally connected crank; Fig. XI is a view in longitudinal section of the link-like piston stem. In this last figure of the drawings this stem is for the sake of simplicity shown as straight; in Figs. II and VI it is shown as curved or arched longitudinally. This characteristic is a matter of structural convenience, to afford clearance during operation. Equivalent adaptations are in the knowledge of the engineer, and accordingly the characteristic alluded to is, in Fig. XI, disregarded.

The engine consists essentially of a cylindrical rotor 1, which I shall term the drum,

concentrically and integrally mounted upon a shaft 4, and rotatable snugly within a cylindrical casing 2. The casing is accessible for assembly and separation of parts by having one head formed as a cover plate 3.

The drum contains the engine-driving parts, but, before explaining them and their minute construction, it is to be remarked that the drum is not the rotor member merely; it is the fly wheel of the engine as well, and to that end it is preferably such a heavy casting as the drawings indicate. The chambers within it and the contained parts are preferably disposed, as the drawings show, symmetrically about the axis of lo tation, to the end that the rotor being symmetrically weighted may serve to best advantage its fly-wheel function.

WVithin the drum are formed the cylinders. The number of these may be varied, according to need or preference; but, as has been intimated, their arrangement is such as to afford a symmetrical disposition of weight about the axis of rotation. The drawings show two cylinders 5 in diametrically opposed positions. These cylinders 5 are not in the geometrical meaning cylinders at all; they are rectangular in cross section, and their longitudinal extent is along curves, but they are the chambers within which pistons reciprocate to drive the engine, and,

such being the case, they'are functionally cylinders. Accordingly, without further explanation, I shall throughout the remainder of the specification and in the claims allude to these chambers as cylinders, and in the descriptive portion of the specification (relating as it does to the drawings specifically) I shall consistently place the word cylinder, when so used, in quotation marks.

Fig. II shows each cylinder to be sector shaped (of. Fig. III), in that its heads are formed by planes which are approximately radial to the cylinder to which the drumis shaped; while comparison of Fig. IV with Figs, VI, VII, and VIII, will show the rectangular cross-section.

The cylinder space is, it will be observed, formed wholly within the body of drum 1; the end walls and one of the side walls of each cylinder are formed by the body of drum 1; but the other three side walls are formed by the casing 2 and its cover plate 3.

Comparing Figs. I, III, and IV, it will be observed, further, that the cylindrical drum 1, cut away wholly from head to head to form the engine cylinder, is, in addition, cut away partially, to contain the engine driving connection. These additional cut away portions constitute a central cylindrical space 6 and lateral cylindrical spaces 7, cut through one head of cylindrical drum 1 part way to the opposite head. There are as many lateral spaces '7 as there are engine cylinders 5, and each space 7 communicates with the central space 6 and with one of the engine cylinders as well. The configuration here indicated will be clearly understood by inspecting Fig. III and comparing with it Fig. IV.

IVithin each cylinder a piston 8 is reciprocable. The periphery of the piston is provided with suitable packing, as indicated at 9; and, inasmuch as drum 1 in the operation of the engine rotates within the casing, the drum carries packing 10 disposed between itself and the casing, where the gases withinthe cylinders would otherwise find egress.

Interconnected pinions (the drawings show such interconnection in simplest form by showing the pinions intermeshing directly, one with the other) 11 and 12 are borne, one rigidly by the casing, thcother rotatably by the drum. Pinion 11. arranged within the central space 6'is concentric with shaft 1 and drum 1. Figs. I, II and IX show how this is structurally accomplished: pinion 11 is formed integrally with, and as a flange-like extension from a sleeve 13, which sleeve 13 is bolted to the cover plate 3 of the casing (the drum 1 is so disposed within the casing that the spaces 6 and 7 open toward the cover plate). There is a pinion 12 in each space 7, and each is journaled on a stub shaft 14: extending centrally within the space from the body of drum 1. The engine of the drawings being (as presently will more clearly appear) a four-cycle engine, pinion 11 is provided with just twice as many teeth as is each pinion 12. The effect is that as shaft 4 rotates the pinions 12 make planetary motion around it, and in the course of one rotation of shaft (and of drum 1, integral with the shaft), each pinion 12 will make two complete rotations on its shaft 14. Each pinion 12 carries iutegrally with itself a crank 15, and piston stems 16 form links connecting each piston 8 with the crank 15 of the adjacently arranged pinion 12. From this construction it follows that as shaft 45 turns, and pinions 12 describe their planetary motions around it, pistons 8 reciprocate in the engine cylinders 5; and careful consideration of the drawings will show that, given the proportion and relative arrangement of parts shown, in the course of a single revolution,

each piston will make two complete double strokes, forward and back, through its cylinder.

Referring particularly to Fig. II, and premising the fact that the direction of r0- tation is, as the parts are there shown, clockwise, it will be noted of the cylinder 5 there shown to be uppermost, that the piston 8 within is at one end (the right-hand end) of the cylinder. .As shaft t turns clockwise, carrying with it drum 1, this pisten 8 will, because of the rotation of pinion with which it is linked, gradually move in a right-to-left direction. toward the opposite end of the cylinder. This movement. will continue throughout approximately one-fourth of a rotation of shaft 1. During this approximate quarter rotation of shaft 4 pinion 12 will have made approximately a half rotation (relatively to pinion 11), and piston 8 will have shifted to the opposite end of the cylindeito the position indicated in dotted lines. in the upper part of Fig. II. During the remainder of the first half of a rotation of shaft 4 pinion 12 will, relatively to pinion 11, complete a full revolution (relatively to the stationary casing 2 it is but a half revo lution), and piston 8 will return to its initial position (that of the companion and opposite piston, as shown in Fig. II). During the second half rotation of shaft 4, piston 8 within cylinder 5 will similarly travel through a second complete return traverse. Thus it appears, as has already been said, that, in one rotation of shaft 4, each piston in each cylinder makes two complete double strokes, forward and back; and, as indicated in Fig. II, these four strokes are the four cycles. During the first cycle, while the piston which is uppermost is moving from the full-line to the dotted-line position, the cylinder is taking in the explosive mixture; during the second cycle, while the piston is advancing again to the full-line position, the charge of explosive mixture so previously taken in is being compressed; during the third cycle the now ignited and exploded gases are driving the piston to the dotted-line position; and, during the fourth cycle, the cylinder having now come into communication with an exhaust port, the returning piston is driving before it and out from the cylinder the resultant and now spent gases.

It remains to explain the inlet for the explosive mixture, the ignition device, and the exhaust for the spent gases. The inlet and the exhaust are arranged in opposite heads of the cylindrical casing 2, 3, and (the cylinders 5 being formed by cutting entirely through the cylindrical drum 1 from head to head) these cylinders 5 as the drum rotates come into open communication with inlet and exhaust ports. As best shown in Fig. I, the inlet port 35 opens through the head of easing 2 from a supply pipe 36 which leads from the carbureter. The communication from carbureter to inlet is advantageously controlled by a valve 17. This valve, held normally closed by a spring 18, opens only under the thrust of a cam 19 borne by shaft 4; and the correlation is such that the valve is open when and only when a cylinder 5 is in communication with inlet port 35.

An outlet port 20 (cf. Fig. V) opens through cap plate 3 of the casing to the exhaust 21. The spark plug is indicated at 22. Fig. II.

Referring now to Fig. 11, and with atten tion directed particularly to the uppermost cylinder 5 and the piston 8 within it, it is to be understood that the direction of rotation is clockwise. Beginning with the cylinder in the position shown, the piston is at the right hand end, that is to say at the bottom of the cylinder. As the drum turns. and during approximately the first quarter rotation of shaft 4 and drum 1 the piston 8 traverses the cylinder from the full-line to the dotted-line position, enlarging the cylinder space beneath the piston from minimum volume to maximum. During this portion of the rotation the space within cylinder 5 beneath piston 8 is in free communication with inlet port 35 and valve 17 is open. Accordingly the cylinder during this quarter revolution sucks in and becomes filled with the explosive mixture. During the second quarter of the revolution the cylinder space 5 has passed beyond the inlet port, and the valve 17. released from the action of cam 19, has under the influence of spring 18 closed again. The cylinder 5 is cut off from external communication. Meanwhile piston 8 within cylinder 5 is descending again, compressing the charge of explosive mixture within cylinder 5,until the parts come. at the completion of the second quarter of the rotation, to the fullline position shown in the lower half of Fig. II. (It will be understood that Fig. II shows two cylinders 5 and two pistons 8, arranged at diametrically opposite points, and that each part as shown illustrates the position to which the opposite part will come after a half revolution of drum 1.) 1

When this point is reached the space within cylinder 5 and beneath piston 8 comes into communication with the spark plug 22, and immediately ignition is accomplished. During approximately the third quarter of the rotation the piston 8 is traversing its cylinder, as it was during the first quarter, and during this portion of the rotation, as during the second quarter, the cylinder is closed. During the fourth quarter of rotation piston 8 is returning from the top to the bottom of the cylinder, and the cylinder chamber beneath the piston is during this portion of the rotation in communication. through exit orifice 20, with exhaust 21.

It remains to say that (while it is true that rotation of shaft 4 and of drum 1 effect, through the pinions and crank and link connection described, the reciprocation of the pistons S in their cylinders) it is the expansive power of the exploded gases, acting within each cylinder through the third quarter (or cycle) of its rotation, which, through the connections alluded to, efiects rotation of shaftand drum. These operative connections thenpinions, cranks, and link-are the means through which, at one instant, the shaft drives the piston, and at another instant, the means through which the piston drives the shaft.

It will be understood without detailed showing that the cylinders 5 to rearward of or above the pistons 8 may at proper portions of the range of rotation and through proper ports be in free communication with the open air. Further, it will be understood that the link and pinion connection between piston and drum is such as to forbid retrogression of the drum and to comdriven, to afford with the aid of well-known F instrumentalities (not shown) timed discharges in spark plug 22.

The structure of the drawings is exemplary, and in the practice of my invention the engineer is expected to avail himself of structural variations such as lie Within his unaided knowledge. In the ensuing claims I define what is of the essence of my invention. If this be employed myinvention will be practised, whatever be the incidental departures in structure from the exemplary showing here made.

I claim as my invention:

1. In a rotary explosive engine the combination of a shaft, a. cylindrical body axially borne upon and integral with said shaft and having formed within itself a cylinder whose axis extends in a curve centering in the axis of shaft rotation, the weight of said cylindrical body being symmetrically disposed relatively to that shaft axis, a piston reciprocable in said cylinder, means interposed between piston and shaft whereby as the shaft turns the piston reciprocates and whereby driving stress upon the piston within the cylinder exerts a rotary strain upon the shaft, means for periodically and successively in the course of rotation introducing into said cylinder an explosive substance and for igniting such explosive substance when so introduced, substantially as described.

2. In a rotary explosive engine the combination of a shaft, a cylindrical body axially borne upon and integral with said shaft and having formed within itself a plurality of cylinders symmetrically disposed relative to the shaft axis,each cylinder being curved longitudinally on a curve centering in the axis of rotation, a piston reciprocable in each ofsaid cylinders, means operative as the shaft rotates for successively introducing into said cylinders charges of explosive substance and means operative in sequence for exploding such charges, and means for communicating the power of explosion from the pistons to the shaft, substantially as described.

3. In a rotary explosive engine the combination of a cylindrical casing, a rotary shaft axially arranged within the casing, a cylindrical drum concentrically borne upon said shaft and within said casing, a cylinder formed in said drum, sector shaped in longitudinal section, rectangular in cross section and closed peripherally by the casing which forms its outermost side wall, a piston reciprocable in said cylinder, and means interposed between piston and shaft whereby as the shaft turns the piston reciprocates, and whereby driving stress upon the piston within the cylinder exerts a rotary strain upon the shaft, substantially as described.

4. In a rotary explosive engine the combination of a shaft, a chambered cylindrical drum axially borne upon and integral with said shaft, and a cylindrical casing within which said drum may rotate, such chambered' drum having formed within itself a cylinder curved longitudinally on an arc centering in the axis of shaft rotation, a crank chamber, and a pinion chamber, a piston reciprocable in said cylinder, a pinion having a crank united to it journaled in the drum body and rotatable within the crank chamber, said crank being linked to said piston, a pinion within said pinion chamber borne by said casing and meshing casing within which said drum is rotatable,

a cylinder rectangular in cross-section and; I

curved in longitudinal extent formed within said drum with the center of its longitudinal curvature coincident with the axis of shaft rotation, a crank chamber formed within said drum and opening to said cylin= der at one end thereof, a pinion chamber formed within said drum concentric with the axis of shaft rotation and communicating with said crank chamber, a piston in said cylinder, a pinion in said crank chamber, having a crank formed integrally with itself, and being through such crank linked to said piston, a pinion in said pinion chamber borne by said casing and intermeshing with the pinion in the crank chamber, means for introducing explosive material to said piston at one point in the course of rotation and means for exploding such material with in the cylinder at another point in the course of rotation, substantially as described.

6. In a gas engine of rotary type, the combination of a shaft, a cylindrical drum borne by the shaft and rotatable within a a cylindrical casing, said drum serving at once as a fly wheel for the rotating shaft and a carrier for the driving parts, recesses formed peripherally in said drum breaking its cylindrical continuity, said recesses bein inclosed to constitute cylinder chambers by the unbroken cylindrical walls of the inclosing casing, pistons in the cylinder chambers so constituted, driving connections between pistons and shaft, inlet and discharge ducts opening to each of said cylinder chambers in the course of drum rotation and means for exploding successive charges compressed Within said cylinder chambers, the said cylinder chambers, pistons and driving connections being symmetrically disposed with respect to the axis of rotation.

FRED KELLER, JR. 

